Help with aluminum radiator. Epoxy, brazing?

ricardoa1

ricardoa1

Registered User
I have a problem. I bought a used radiator from a member last year I failed to inspect the item at the time since I didn’t plan on using it till later. Anyways the item came in damaged. The water cap neck was pushed in during shipping, I decided to bend it back into shape and pop it back up since I could not get a radiator cap back on. I fixed the lip and lock mechanism of the radiator cap neck but while pulling and tugging on it I broke what seems to be an epoxy seal, where it meets the upper tank. I though the neck was going to fall off at that point but it looks like its brazed deeper inside. I think the inside braze is ok. I then decided to melt the outer epoxy off and repair. I bought some of those as seen on tv no flux rods. And tried to fix it with MAPP gas. But the rod material didn’t want to stick to the radiator parts. Anyone know what I can use to fix this? Currently there is nothing between the neck and the tank, he neck is solid because of the inner brazing but it will leak as it is. I am also afraid I damaged the epoxy brazing that goes to the reservoir. So what should I use to fix it?
 
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You need more heat captain! MAP gas is not enough. The radiator needs to be HOT and it dissipates heat quickly. The reason the rod isn't sticking is cause the part you are trying to weld is not hot enough. Its like soldering, if the wire isn't hot enough it wont work.

Is it a stock radiator or an aluminum one?
 
Some pics for some visuals

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for certain, getting enough heat into the joint is where your problem lies. Even with low temperature brazing rods, you have to get the surfaces up to a basic temp. Just about any video or info you see on soldering or brazing an aluminum radiator for repair, they are using an oxyacetylene torch to generate the heat. Mapp won't cut it on something that massive.
 
That looks like it might react well to a nice bead of black silicon RTV... Hey.. dont knock it. Ive seen that sort of jethro repair on a radiator and it worked.
 
Get a welder to tig weld it for you. If you put too much heat into it, you will separate the core from the tank and end up with a different leak. You also need to clean that crap of the metal or it will never stick. Sand it or clean it with a stainless wire brush. Muriatic acid will strip it off too. Just don't leave it on too long.
 
Ok so what professional epoxy can use and find at the stores? These radiators were being sold for less then 100 dollars at some point, i paid 75 used. I already sunk 15 bux worth of rods. If i bring it to a shop for them to charge me 50 plus, might as well just toss this as scrap metal and get a new one. Rtv seems like too temporary of a fix.
 
Thats the type of rod I have. I think they are all the same just different branding and manufacturere. Its a no flux solder/brazing rod.
 
Im pretty sure that stuff isnt a brazing rod, its a low temp stuff, works with a propane torch it says, you cant braze with a propane torch. Gotta get the radiator an equal temp tho.
 
The problem with that rod is the metal being fixed has to be up to temp which for aluminum is 700*.

Here are some links. Welding tips and tricks has it straight. http://www.weldingtipsandtricks.com/aluminum-brazing-rods.html

I have used HTS 2000. Here is a video for their stuff. http://www.aluminumrepair.com/video_new.asp

I don't think the silicone will hold up to the pressure in the system. It will just push it out. If you do used silicone use the stuff for waterpump gaskets it holds up better to antifreeze.
 
Show me where you can buy an aluminum radiator for $100.


That aside, does it leak? The crap you cleaned out wasn't the weld, it's welded inside as you said. The epoxy stuff was probably just there to give support to the weld. If the weld still holds water, then just put some JB around that to support the neck.
 
XR7 Dave said:
Show me where you can buy an aluminum radiator for $100.


That aside, does it leak? The crap you cleaned out wasn't the weld, it's welded inside as you said. The epoxy stuff was probably just there to give support to the weld. If the weld still holds water, then just put some JB around that to support the neck.
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http://www.sccoa.com/forums/showthread.php?t=122951&highlight=aluminum+replacement+radiator

I referenced this post for pricing.


I put some water in it and flipped it upside down. I think water was leaking from it. But I didnt really think hard on how its pieced together inside. I think an epoxy would be the best bet. But I just want a good solution to fix it.
 
XR7 Dave said:
Show me where you can buy an aluminum radiator for $100.


That aside, does it leak? The crap you cleaned out wasn't the weld, it's welded inside as you said. The epoxy stuff was probably just there to give support to the weld. If the weld still holds water, then just put some JB around that to support the neck.
Click to expand...

Shepard auto parts sells and aluminum radiator. And it used to be 85 bucks.:eek: I picked one up for my 5 speed car and shortly after the price jumped up big time. So no you can't get an aluminum rad for under 100 anymore.

But the 94-95 is still 123.00 and the early model is 190. http://www.shepherdautoparts.com/all_aluminum_radiator/ford/thunderbird.html
 
Nothing you put on the outside will seal a leak. If it is leaking you'll have to get it welded. Still cheaper than buying a new one. However, if there is crap in there, it may not weld very well either. Might have to cut that neck off and weld in a new one.
 
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